Atmasphere MA-1: mk1 vs. mk2?

There are currently a few Atmasphere MA-1 mk1 amps up for sale. Since they look quite different from the mk2, I wondered, how much of a difference is there between these two versions? Do they sound quite similar? Any reliability issues with the mk1? Is it possible/necessary to upgrade parts in the mk1? And do they mind any slight dips down to 3 Ohms in speaker impedance (Audio Physic Virgos)?
Your questions are specific enough that you should call Ralph at Atmasphere. He's a nice guy and will not mind helping you. Plus, there is no question as to the reliability of the answers you will get.

Albert makes a good suggestion. Ralph was extremely helpful to me when I was considering buying a used MA-2. There was never any question about my buying used versus new, he was more than willing to answer all my questions even though my decision to buy used would in no way benefit him. You can also reach him via e-mail from his website:
I also have second-hand testimony as to RK's willingness to assist in advising on used Atma-Sphere purchases. Don't expect this kind of magnanimous treatment from say, Luke Manley at VTL, or Richard Vandersteen. I wish more manufacturers understood the worth to them of helping to keep their gear's resale value and desireability high, instead of short-sightedly disparaging those whose second-hand purchases ultimately help fuel a robust primary market.
I have owned a pair of MA 1s for 6 years now and still consider them to be my last amps. I do believe they are best mated with 8ohm spks. They are the same circuit as the MK2 and sound the same. I run Proac3.5's and it is a great match.mike